Cutting spirals and helix's with standard rocking and rosette

First photo shows a spiral cut using a standard 24 bump sinewave with a 3mm amplitude, the lead angle is 25 degrees.
Second photo shows a spiral cut using a standard 48 bump sinewave with a 3mm amplitude, the lead angle is 30 degrees.
Third photo shows a double spiral or herringbone cut using a standard 48 bump sinewave with a 3mm amplitude, the lead angle is 30 degrees both left and right.
Fourth and fith photos shows the cutter cutting the spiral in photo 1, cutter is set to 25 degrees same as lead angle of spiral.
Photos 6,7 and 8 show the extra slide set at the lead angle of 25 degrees so as the job rotates it gives the bumps but because the tool is set to follow the lead angle you end up with a spiral.

Down side is this method is only good for short and not to steep leads as either side of centre the job curves away from the cutter, cutter is set centre height at centre of travel.
So you need to adjust the depth as it moves out to the outer edges, you start in the midlle cut to both edges at the centre depth then go from the centre out in both directions adjusting the depth as you go.

The next experiment will be cutting gozintas:? and gozoutas:? on the lid of a box using a rosette, single start, 2 start, 3 start, and 4 start ( this means spirals going in and spirals going out:doh:)

Cheers
Tony

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